In recent years, from the viewpoint of saving space and energy, display devices such as liquid crystal display devices, plasma display devices and organic electroluminescent (EL) display devices have been increasingly used. Currently, display devices are required to display an image with a higher resolution and in a wider color gamut (in a wider color reproduction range).
In future, ultra-high-definition television broadcasts will start. However, they cannot be addressed by conventional display devices provided with LED light sources having wide-band emission wavelength characteristic.